TakeNote - A web-based note-taking app with GitHub sync and Markdown support.
Remember The Milk - Remember The Milk is a task and time management application for mobile devices.
NoteAway - NoteAway is the simplest, most convenient way to take quick notes on OS X.
OnlineNotepad.org - Free browser-based text editor
PlicPad - Shareable notepad without urls
aNotepad - anotepad.com is an online text editor that you can write notes and anotepad also has great stability